Low permeation hoses are often used in systems to eliminate or reduce escape and/or infiltration of vapors and/or gases. For example, such hoses may be used in refrigeration systems to prevent leakage of refrigerant vapors from the system into the environment. Such hoses are also common in fuel systems for preventing fuel vapors from escaping to the environment.
Another application of such hoses is in connection with heating systems for supplying and returning water (or other fluid) from one or more heat exchangers. In such applications, low permeation hoses are used to prevent oxygen from entering the heating system, which can result in corrosion of various components such as pumps and valves.
Low permeation hoses typically include an inner tube for carrying a fluid, and a vapor barrier layer surrounding the inner tube. Various other layers typically may surround the vapor barrier layer, such as a braiding, an outer tube, a cover or outer sheath, etc.
One such ultra low permeation hose is disclosed in International Patent Application PCT/US2008/78287, filed Sep. 30, 2008, entitled “Aluminum Foil Based Hose” is hereby incorporated by reference.
A problem with low permeation hoses is that while the hose may be effective in reducing or eliminating leakage, the couplings at the ends of the hose may allow leakage around the end of the vapor barrier.